Characterization of Porcine Granulosa Cell Line AVG-16

Commercially available, but not yet characterized, the AVG-16 granulosa cell line was established from granulosa cells of medium porcine follicles. To examine the suitability of the AVG-16 cell line for studying the molecular mechanism of action of various environmental oestrogens, we investigated: 1/ cell morphology (by standard haematoxylin and eosin (HE) staining); 2/ basal and follicle-stimulating hormone (FSH) or luteinizing hormone (LH)-stimulated steroid hormone (progesterone; P4 and 17β-oestradiol; E2) secretion (by radioimmunoassay) and 3/ expression of receptors involved in the regulation of granulosa cell function: FSH receptor (FSHR), LH receptor (LHR), oestrogen receptor α (ERα), oestrogen receptor β (ERβ) and aryl hydrocarbon receptor (AhR). mRNA and protein expression was determined by RT-PCR and fluorescence immunocytochemistry, respectively. The secretion of P4 and E2 by AVG-16 cells was in the range of steroid hormone secretion by porcine cultured primary granulosa cells. Neither FSH (100 ng/ml) nor LH (100 ng/ml) affected P4 and E2 secretion by AVG-16 cells. The presence of FSHR and LHR at both mRNA and protein level was not demonstrated in the cells. However, AVG-16 cells were found to express mRNA and protein of ERα, ERβ and AhR. The results of our study showed that AVG-16 cells possess the capability of steroid hormone production, and both oestrogen receptors and AhR are present in these cells. Therefore, AVG-16 cells may serve as an unlimited source of homogenous porcine granulosa cells useful for studying the effects of environmental oestrogens on ovarian physiology.